Updated the install script for Arch Linux and the README.md file

[Pazitos10]

I don't know how much popular is this repo but I remembered I used it in the past to download the font. I like that it evolved to allow to download other fonts too. I updated my distro install script to use ~/.fonts/TTF/ as the default installation directory and does not require sudo to be executed anymore. It also checks if the URL argument is present before attempting to run. I think similar changes can be done for the other distros scripts without much hassle but I cannot test those. Finally, I also updated the README.md to add instructions on how to run it on Arch Linux. Thanks for not archiving nor deleting the repo!

[15d23]

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